An ink-jet system which ejects inks in liquid droplets from an ink emitting port is employed in many printers for the reason that it is compact and inexpensive and it is capable of forming an image without contacting a recording medium.
In recent years, ink-jet printers have not been limited only to photographic printing and document printing for home use or office use, and the development of commercial printing equipment and industrial printing equipment employing ink-jet printers has been carried out in advertising, poster, or ornamental utilization. According to this situation, it is strongly demanded for conventional ink-jet inks and ink-jet recording printed products for home use or office use to have (1) high quality in a formed image and (2) an ability to carry out printing on various recording media including non-absorbable recording media such as plastic media so as to be capable of being used as ink-jet inks and ink-jet recording print products suitable to commercial printing or industrial printing.
Conventionally, ink-jet inks, recording devices and methods used in printing for home use or office use (hereinafter abbreviated as ink-jet ink and the like including ink, device and method) have often been developed for the purpose of printing photographs or documents. For this reason, when recording is carried out on a non-absorbable recording medium by use of conventional ink-jet ink and the like, if it takes a long time for drying of the ejected liquid droplets or permeation thereof into the recording medium, there are the problems that the image is easily blurred, and the mixing of adjacent ink liquid droplets occurs on the recording medium, thereby preventing a sharp image from being formed. Moreover, when an image is formed on a non-absorbable recording medium, there are the practical problem that the fixation properties of the image are not good, that is, it is easily peeled off from the recording media, the abrasion properties are poor, and the like. Also, when applied to high-speed printing, liquid droplets are displaced from the positions at which they landed, because the adjacent liquid droplets coalesce after ejection and move, thus causing the problems that color unevenness and the like are generated due to droplet-interference, that is, a line width is non-uniform when drawing fine lines and color unevenness and the like are generated when drawing a color surface.
In this specification, hereinafter, the properties such as abrasion properties and easiness of peeling will be referred to as “fixation properties” and the properties concerning image qualities such as color unevenness and non-uniformity of line width will be referred to as “drawing properties”.
As means for solving the above problems, various technologies have been proposed so far, which include, for example, technologies for improving the components and constitution of ink itself (for example, Patent Document 1) and technologies for improving an ink-jet recording device or method (for example, Patent Document 2). However, the technologies disclosed in the above documents have failed to sufficiently solve the problems concerning the fixation properties of an image recorded in a non-absorbable recording medium, which problems are considered to be important in particular commercial or industrial print products. Patent Document 3, on the other hand, discloses that a primer is adopted, and the primer is to semicured to perform single pass printing in a recording method in order to solve the fixation property problem. Patent Document 3 also describes or suggests ink or primer components, preferable physical properties of these compounds, and a relationship between the both. This is intended to solve the fixation property problem from an overall point of view.